Rocket engine



July 19, 1938. 'c. R. cuMMlNGs ROCKET ENGINE 2. Sheets-Sheet 1 Filed Aug. 18, 1937 *Eng . IMI 4 l u/ x f 114155445nivnnvafnlvffnr? hull? lla/figuran mvr-:N'ron Bf ATTORNEYS July 19, 1938. c. R. CUMMINGs l RCKET ENGINE Filed Aug. 18, 1937 2 Sheets-Sheet 2 mzw.,

ATTORNEYS Patented July 19, 193s UNITED STATES ROCKET ENGINE Charles R. Cummings, Fernwood, Pa. I

Application August 18,

1937; Serial N0. 159,762

a claims. (c1. so-35.6)

This invention relates to rocket engines and has for an object to provide a novel single piston unit wherein the explosive impact of fuel gas is exerted directly against the atmosphere thus utilizing the force to its fullest extent and permitting the use of avery light structure. A further object is to provide novel means for controlling the supply of explosive gas and airy so that maximum propulsion will be obtained l0 due to the reaction caused by the gases escaping from the rocket.

A further object is Ato provide apparatus of this type which will be formed of a few strong,

simple, and durable parts, which will be light and L compact, which will be inexpensive to manufacture, and which will not easily get out oi order. With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to Within the scope of the appended claims without departing-from the spirit or sacrificing anyv and secondary induction coil contacts of the ignition switch.

Figure 4 is a front elevation of the movable switch arm showing the primary and secondary induction coil contacts.

Figure 5 is a sectional view of the switch arm showing the secondary contacts connected together so that the explosion in each cylinder will :dre the next succeeding cylinder.

Figure 6 is a cross sectional view taken on the line 6 6 of Figure 1.. l l

Figure '7 is a detail cross sectional view taken 5o on the line 'l-1 o1' Figure 1 showing the mounting of the gas valve.

Figure 8 is a cross sectional view taken on the line 3-3 oi Figure 1 showing the valve and the piston in rear elevation.

55 Figure 9 is a diagrammatic view showing the 1ignition devices 'and electrical connections thereor. Y

Referring now to the drawings in which like characters of reference designate similar parts in the various views, each unit of the engine is shown to .comprise a cylinder I 0 which is closed at the front end II and is reduced and open at the rear'end I2. The cylinder is provided with longitudinal cooling ns I3 extending throughout the length of the combustion chamber at the rearl end of the cylinder. A piston I4 is slldably mounted in the cylinder and is provided with a skirt I5 which forms a valve to control admission of acombustible mixture into the cylinder 'from the mixing chamber I6. 15

The mixing chamber extends obliquely to the axis ofthe cylinder and is provided with a port, I'I through which thenmixture enters the cylinder when a similar port |81 in the piston skirt I5 is in registration therewith. The mixing chamber 20 communicates with the atmosphere through an air port I6 at the bottom.

The cylinder I0 is mounted on a suitable supv porting bracket I9 which may be of any suitable shape to dispose a plurality of the cylinders either in a row or-in the form of an annulus,A and in either parallel relationship or staggered `relationship. Y

' A valve housing 20, best shown in Figure '7, is provided with mounting ears 2| which-are bolted as shown at 22 to the support I 9. A plunger type valve 23 is mounted in the housing 20. A gas pipe 24 enters a valve seat 25 which is screwed into the housing and a gland nut 26 is screwed on to the seat-to' provide a leak-proof joint. The free end of the pipe enters the mixing chamber and is bentto extend along the axis of the chamber and provide a discharge nozzle 21.

` A gas supply pipe 23 is formed integral with the housing and projects into the channel of the support I9 where it is coupled to the gas line 29 -by a coupling 30. 'Ihe rod 3ly of the piston I4 is c onnected by a rock -link 32 to the rod 33 oi the piston type va1ve23. A helical spring 34 is sleeved on the rod 33 and, as pressure of exploded gas in the combustion chamber recedes the spring opens the gas valve 23 and simultaneously pushes the piston I4 back to open the ports I'l and I8 for supplying the combustion chamber with a new charge. i

In frontv oi' the piston rod 31| a stationary switch member 35, formed of insulating material, is iixed in the front end ofthe lcylinder. A switch arm 3B is pivoted in the cylinder betweenV the stationary switch member 35 and the end of 55 combustion chamber.

in any desired order but in the present embodiment of the invention a number of cylinders A are f fired in predetermined order and the i'lring o! these cylinders is adapted to fire the next succeeding number of cylinders B in predetermined order through the electrical connections of the switch members, as shown diagrammatically in Figure 9.

The stationary switch member 36 of each cylinder is provided with a pairof switch contacts 3S and with a single switch contact 40. One of the switch contacts 39 is connected to the spark plug 38 of the next succeeding cylinder by conductor wire 4l. The other contact of the pair is connected by a wire I2 to one end of the secondary winding I3 of a vibrator type induction coil M.

. The single switch contact Il is connected by a cylinder, under pressure? cylinder.

wire 45 to'one end or the primarycwmdmg As or the induction c'oil.

The movable vswitch arm u is also provided with a pair of switch contacts I1 which are connected together by a metal plate It, as best shown in Figure 5, so that when the switch arm is in circuit closing position the high tension ignition circuit isiclosed to re the spark plug of thenext adjacent cylinder. The switch arm is also provided with a single switch contact 49 which is grounded by a wire 50, to the cylinder. Thus the primary circuit of the induction coil will be closed when the switch arm to cause the vibrator type coil to operate and fire the next succeeding cylinder when the explosion in a particular cylinder has moved the respec,

tive piston to mve'the respective switch arm to circuit closing position.

In operation, gas or vaporlzed fuel of any desired type enters the combustion chamber of the vThe jet of -gas draws atmospheric air through the air port It' mixing chamber I6 from which the explosive mixture escapes into the cylinder. The gas mixture is red by the next preceding cylinder. 'I'he explosion moves the piston Il forwardly so that the switch arm 3G is moved to circuit closing position to immediately fire th`e next succeeding bustion chamberV recedes, the valve spring 34 simultaneously opens the gas control valve 23 and is in circuit closing position in normal position, means As pressure of spent gasesvinthe com-- cylinder, a connection between the piston and the valve arranged in such manner that movement of the piston under impulse of the explosion simultaneouslyeifects closing of the'switch and the seating of the valve, and means connecting the spark plug of each cylinder with the switch of the preceding cylinder and arranged in suchmanner that closing of theswitch in one cylinder res the next succeeding cylinder.

2. In a rocket engine, a cylinder closed at its front end and having its rear end reduced and open, a piston slidably mounted in the cylinder, a spark plug extending into the cylinder. a mixer. communicating with the cylinder rearwardly of the piston, a switch mounted in the vcylinder forwardly of the piston, and including a fixed contact and a movable contact, forward movement of the piston under impulse of the explosion moving the movable contact an ignition switch controlled by the switch for energizing the spark plug, a fuel controlled valve connected to the mixer, and a connection between the piston and the valve arrangedin such manner that forward movement of the piston under imto circuit closing position,v

in the cylinders, a mixer connected to ,each cyllinder communicating with the cylinder in rear of the piston, a skirt on the piston sealing the mixer during the explosion and unsealing the mixer for supplying fuel to the mixer, ignition means for each cylinder, ignition circuits for the cylinders, a switch in each cylinder controlling the ignition' circuit of the next succeeding cylinder, a rod on each piston adapted to close the respective switch when the piston ismoved forwardly under impulse of the explosion, and a pivoted rock link connected to the piston rod and to the valve'and adapted to seat the valve when the piston is moved forwardly.

CHARLES R. CUMMINGIS.v 

